Ecosystem Ecology Flashcards
Define ecosystem ecology
Study of communities of organisms and the physical environment they occupy
Physical and biological components of ecosystems are linked by what?
- Cycle nutrients within system
2. Transfer energy through system
Ecosystems are involved in what types of interactions?
Abiotic and Biotic
Describe the function of an ecosystem
Energy from sun flows in one direction (energy entering is processed then transformed)
Matter is recycled within ecosystem (results in outputs: heat, water flow, waste products)
Species interactions result in food chains/webs that re-cycle what?
How do they do this?
Carbon and other elements
Through photosynthesis, chemosynthesis, cellular respiration, decomposition
What are the most important interactions within communities and why?
Predation and herbivory because they are major links to the carbon and nutrient cycles
Ultimately ecosystem function depends on what?
Autotrophs to form organic molecules by reducing carbon
Photoautotrophs-photosynthesis
Chemoautotrophs-chemosynthesis
Material cycle in communities through what?
Various trophies levels
Primary producers–>consumers–>decomposers
How does energy flow through ecosystems?
Species interactions form tropic pyramids that transfer energy through ecosystems
Energy does cycle within ecosystems
TRUE OR FALSE?
FALSE
New energy must be what to sustain an community?
Continually harvested
Some energy is stored in the chemical bonds or organic molecules (carbohydrates) by who?
Producers
Relatively small amounts of energy is transferred from one trophies level to the next based on…
Allocation
Explain the principle of allocation of energy
Each organisms has a limited amount of energy available for allocation for:
- maintenance
- obtaining food
- movement
- dealing with predators
- coping with change
- growth
- reproduction
From the base of plant productivity about how much of the biomass of each trophies level is passed onto the next?
10%
Most energy that organisms use is lost as heat through metabolism, this means:
(A) fewer organisms at highest trophic levels where less energy is available
(B) upper trophies levels depend on primary productivity by primary producers through photosynthesis
(C) more organisms at highest trophic levels where more energy is available
(D) each energy level contains 20% of the energy from the trophic level below
(E) none of the above
(F) A and B
(G) A and D
(F) Both A and B
Define productivity
Rate of generation of biomass
Expressed in units of mass per unit surface or volume per unit time
Define Primary productivity
Rate of generation of biomass by photoautotrophs
Light and water availability can limit primary productivity
Aquatic ecosystem have a what limitation?
Light
Terrestrial ecosystems have a what limitation?
Water
Define nutrients
Elements and compounds required for survival that are consumed by organisms
Define macronutrients
Nutrients required in large amounts (nitrogen, carbon, phosphorus)
Define micronutrients
Nutrients needed in small amounts
Nitrogen and phosphorus are important for what growth?
Nitrogen and phosphorus
Law of Minimum
For every population there will be one limiting resource which determines the carrying capacity of the habitat
The Earth is?
Closed system for matter
Open system for energy
How is energy introduced to the system?
Energy from sun and radioactive decay in interior magma drives processes that move matter
Processes moving matter are referred to as?
Biogeochemical cycles
Define pools (reservoirs)
Where nutrients reside for varying amounts of time
Define Flux
Movement of nutrients among pools, which change over time and are influenced by human activities
Define Sources
Pools that release more nutrients than they accept
Define sinks
Pools that accept more nutrients than they release
What are the 3 nutrient cycles?
- Carbon
- Nitrogen
- Phosphorus
Explain the Phosphorus cycle
Weathering–>runoff–>upwelling–>sedimentation–>tectonic uplift
